Learn Environmental Chemistry MCQ questions & answers in Inorganic Chemistry are available for students perparing for IIT-JEE, NEET, Engineering and Medical Enternace exam.
1.
Global warming is due to increase of :
A
methane and nitrous oxide in atmosphere.
B
methane and $$C{O_2}$$ in atmosphere.
C
methane and $${O_3}$$ in atmosphere.
D
methane and $$CO$$ in atmosphere.
Answer :
methane and $$C{O_2}$$ in atmosphere.
The main gas responsible for the global warming is carbon dioxide. Other contributors include methane released from landfills and agriculture.
2.
The region which is greatly affected by air pollution is
A
thermosphere
B
stratosphere
C
troposphere
D
mesosphere
Answer :
troposphere
Air pollution greatly affect the troposphere.
3.
Which of these are biodegradable pollutants?
(i) Pesticides
(ii) Mercuric salts
(iii) Sewage
(iv) Radioactive wastes
A
(i) and (ii)
B
(i) and (iii)
C
(i), (iii) and (iv)
D
(iii) only
Answer :
(iii) only
Only sewage is biodegradable.
4.
$$10\,mL$$ of water requires $$1.47\,mg$$ of $${K_2}C{r_2}{O_7}$$ $$\left( {M.\,wt. = 294} \right)$$ for oxidation of dissolved organic matter. $$C.O.D.$$ is
A
2.44 $$ppm$$
B
24 $$ppm$$
C
32 $$ppm$$
D
1.6 $$ppm$$
Answer :
24 $$ppm$$
$$10\,mL$$ water $$ = 1.47 \times {10^{ - 3}}\,g\,$$ of $${K_2}C{r_2}{O_7}$$
$${10^6}\,mL$$ of water $$ \equiv 147g$$ of $${K_2}C{r_2}{O_7}$$
No. of gm equivalents of dichromate reacts is equal to the no. of gm equivalents of oxygen required.
$$\therefore 49\,g$$ of $${K_2}C{r_2}{O_7}$$ requires $${O_2} = 8\,g$$
$$\left[ {gm.\,eqv.\,\,{\text{of}}\,\,{K_2}C{r_2}{O_7} = \frac{{294}}{6} = 49,\,gm\,eqv.\,\,{\text{of}}\,\,{\text{oxygen}} = 8} \right]$$
$$\therefore 147\,g$$ of $${K_2}C{r_2}{O_7}$$ will require $${O_2} = \frac{{8 \times 147}}{{49}} = 24\,g$$ $$\left[ {24\,g = 24\,mg/L = 24\,ppm} \right]$$
5.
Which of the following statements about the depletion of ozone layer is correct ?
A
The problem of ozone depletion is less serious at poles because $$N{O_2}$$ solidifies and is not available for consuming $$CI{O^ \bullet }$$ radicals.
B
The problem of ozone depletion is more
serious at poles because ice crystals in the clouds over poles act as catalyst for photochemical reactions involving the decomposition of ozone of $$C{l^ \bullet }$$ and $$CI{O^ \bullet }$$ radicals.
C
Freons, chlorofluorocarbons, are inert. Chemically, they do not react with ozone in
stratosphere.
D
Oxides of nitrogen also do not react with ozone in stratosphere.
Answer :
Freons, chlorofluorocarbons, are inert. Chemically, they do not react with ozone in
stratosphere.
Freons and chlorofluorocarbon find their way to stratosphere through without being destroyed in the troposphere due to their low reactivity. In the stratosphere the $$Cl$$ and $$Br$$ atoms are liberated from the parent compounds by the action of ultraviolet light
e.g.
$$\eqalign{
& C{F_2}C{l_2} + h\nu \to C{F_2}Cl + Cl \cr
& CFC{l_3} + h\nu \to CFC{l_2} + Cl \cr} $$
The $$Cl$$ atoms can destroy ozone molecules through a variety of catalytic cycles.
6.
The two strong acids present in the acid rain are
No explanation is given for this question. Let's discuss the answer together.
7.
Which of the following statements is wrong?
A
Ozone is not responsible for greenhouse effect.
B
Ozone can oxidise sulphur dioxide present in the atmosphere to sulphur trioxide.
C
Ozone hole is thinning of ozone layer present in the stratosphere.
D
Ozone is produced in upper stratosphere by the action of $$UV$$ rays on oxygen.
Answer :
Ozone is not responsible for greenhouse effect.
Ozone is a greenhouse gas and is responsible for greenhouse effect.
8.
An object is located at a height of 18 $$km$$ from the surface of earth. The object is located in
A
thermosphere
B
mesosphere
C
ionosphere
D
stratosphere
Answer :
stratosphere
Stratosphere extends from 10 $$km$$ to 50 $$km$$ from earth's surface.
9.
Which of the following is a greenhouse gas?
A
$$S{O_2}$$
B
$${H_2}S$$
C
$$C{O_2}$$
D
$${O_2}$$
Answer :
$$C{O_2}$$
Carbon dioxide, methane, water vapour, nitrous oxide, $$CFCs$$ and ozone are greenhouse gases.
10.
Consider the following statements :
(i) Zirconium-Alizarins dye is used for testing fluoride ions in water.
(ii) Ozone layer is present in mesosphere.
(iii) The poisonous gas present in the exhaust fumes of automobiles is $$CO.$$
(iv) Taj Mahal is affected by $$C{O_2}$$ gas.
The correct statements are
A
(i) and (iii)
B
(i), (ii), (iii)
C
(i), (iii) and (iv)
D
all of these
Answer :
(i) and (iii)
No explanation is given for this question. Let's discuss the answer together.